The total cost to build a table is two-folds – one, the cost of raw material consumed and two, the labour cost. Further, the labour cost is calculated as a percentage of the cost of raw material consumed. Due to changes in the supply and labour situation, the price of raw material increased by 25% and also the labour cost increased from 20% of cost of raw material to 32% of cost of raw material. What was the percentage increase in the total cost to build a table?

37.5%

Consider the original raw material cost as 100. Now find the original labour cost.

Next, find the new raw material cost and the new labour cost, as required % of this new raw material cost.

Let original cost of raw material be Rs. 100

Thus, labour cost will be 20% of 100 i.e. Rs. 20 . And original total cost will be Rs. 120.

Now, new cost of raw material will be Rs. 125

And new labour cost will be 32% of 125 i.e. Rs. 40. And new total cost will be Rs. 165.

Percentage increase in total cost = 45/120 × 100 = 37.5%

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